Exercise equipment has been designed for developing and maintaining physical fitness through a variety of exercises. Such equipment includes weight lifting machines, rowing machines, stair climbing machines, treadmills and the like. Such machines, and most exercise regimens are designed to improve the cardiovascular condition of the persons undertaking such exercise and to provide muscle building and muscle toning. Fitness centers and home exercise equipment for accomplishing these purposes are in widespread use.
Although muscle building and muscle conditioning are important in developing and maintaining physical fitness, another part of the physical fitness story is developing body flexibility. Simply stated, a flexible body works better. Good posture, decreased stress, relief of muscular and joint pain, substantially improved physical and athletic ability and an enhanced sense of well being all come with improved flexibility. Inflexibility, particularly in the lower back and hamstrings, causes low back and hamstring pain and injury. A large percentage of the adult population in the United States suffers from lower back pain; and improving back flexibility can reduce or eliminate this type of pain. Although the benefits of such flexibility are important and obvious, achieving flexibility has not been a simple task.
Inactivity and certain exercises, such as bicycle riding and running, cause the hamstring muscles to shorten. Contracting the hamstring muscles causes the pelvis to become unstable. This in turn tends to throw the spine out of alignment, constricting and pinching nerves, including the sciatica, which can cause moderate to severe pain from the lower back though the upper leg. It has been found that stretching before and after exercise reduces or eliminates the risk of injury from fitness workouts or athletic performance.
To properly stretch, the targeted muscles must be in a relaxed or passive state. Solo stretching the hamstring and muscle groups creates an inherent conflict of self-generated stretching force interfering with the passive state muscles. While dynamic or ballistic stretching is an option, it is less effective, and invites injury. Partner or trainer assisted stretching also presents problems. Most obviously, another person is required each time the stretching exercise sequence is undertaken. Beyond this, however, it is difficult, even with a trainer, to produce consistent stretching tension.
An exercising device for stretching the user's back and hamstring muscles without requiring a partner or trainer is disclosed in the U.S. Pat. No. 5,108,090 to Reed . This patent is directed to a power stretching device where the user is seated with the legs extended. A leg-immobilizing unit is provided; and an adjustable extension portion is attached pivotally to a reciprocating telescoping unit. The telescoping unit has handgrips at its upper end for engagement by the hands of the person using the device. A motor controls the reciprocal movement of the telescoping unit to cause it to move toward and away from the person using the device. Thus, as the hand grips move away from the user toward the pivot, the user is pulled forward in a bending position to effect the desired stretching of the back and leg muscles. Although the device of the Reed patent is effective for providing back stretching exercise, the mechanical parts are somewhat cumbersome and complex; and the overall device is relatively large.
Additional patents have been obtained for exercise devices for power-driven exercises. For example, a device for manipulating the legs and arms of users is disclosed in the U.S. Pat. No. 4,478,213 to Redding. The U.S. Pat. No. 5,071,117 to Mautner is directed to an electric bicycle where the movements of the person using the device are effected by the powered operation of the electric bicycle. Other devices using motor driven levers, pulleys and the like have been designed for exercising various muscles of the user. Most of these devices are relatively cumbersome, complex and expensive.
It is desirable to provide an improved power operated stretching device which overcomes he disadvantages of the prior art devices and which is small, compact and easy to use.